1. Field of the Invention
The present invention relates to a color adjusting method and a color adjusting method of adjusting subject colors of a color image to target colors.
2. Description of the Related Art
A general method of adjusting colors of a color image is a correction method using a gamma function. If an image is expressed by R (red), G (green) and B (blue) color components, these RGB color components are corrected using a gamma function (for example, see JP-A-11-143143). Hereinafter, this correction is referred to as gamma correction.
The gamma correction allows adjustment of luminance, contrast and so on of a whole image. Since the gamma function has a smooth shape, a result of correction is smooth, a reversion of gradation does not appear, and the gradation is not lost. However, since an adjustment is performed on the whole image, only a particular color and its surrounding cannot be adjusted which is not effected by other colors.
JP-A-2004-112694 discloses a color adjusting method of adjusting a subject color of a color image to a target color, which is not effected by other colors. In this disclosure, a capsule body including a subject color to be adjusted and a target color is formed in a color space representing the color image, and a color adjustment is performed only in the capsule body. In addition, shift of the subject color to the target color is controlled so as to generate no reversion of gradation. Accordingly, it is possible to preferably adjust a blue color of the sky, a green color of trees and grass, etc., for example, which is not effected by other colors.